Robotic cleaning device and a method of controlling the robotic cleaning device

ABSTRACT

A robotic cleaning device having an inertia measurement unit and a controller. The inertia measurement unit is arranged to sense a displacement of the robotic cleaning device and the controller is arranged to determine a characteristic of the displacement of the robotic cleaning device, and to set the robotic cleaning device in an operational mode being associated with the determined characteristic of the displacement.

This application is a U.S. National Phase application of PCTInternational Application No. PCT/EP2015/058377, filed Apr. 17, 2015,which is incorporated by reference herein.

TECHNICAL FIELD

The invention relates to a robotic cleaning device and a method ofcontrolling the robotic cleaning device.

BACKGROUND

In many fields of technology, it is desirable to use robots with anautonomous behaviour such that they freely can move around a spacewithout colliding with possible obstacles.

Robotic vacuum cleaners are know in the art, which are equipped withdrive means in the form of a motor for moving the cleaner across asurface to be cleaned. The robotic vacuum cleaners are further equippedwith intelligence in the form of microprocessor(s) and navigation meansfor enabling an autonomous behaviour such that the robotic vacuumcleaners freely can move around and clean a space in the form of e.g. aroom. Thus, these prior art robotic vacuum cleaners has the capabilityof more or less autonomously vacuum cleaning a room in which furnituresuch as tables and chairs and other obstacles such as walls and stairsare located.

Modern robotic vacuum cleaners are arranged with a user interface (UI)via which a user of the robotic cleaner may input instructions, such asselecting and scheduling a cleaning program to be performed or forentering data such as time and date. A problem with these ULs is thatthe types of input data which can be entered are rather limited.Further, the size of the UI to be operated by a user is small, making itcumbersome for a user to input data via the UI. Moreover, as with manyelectronic devices, the data to be entered may be perceived asnon-intuitive for a user.

SUMMARY

An object of the present invention is to solve, or at least mitigate,one or more of these problems in the art and to provide an improvedmethod and robotic cleaning device for facilitating, for a user, toprovide the robotic cleaning device with user instructions.

This object is attained in a first aspect of the invention by a methodof controlling operation of a robotic cleaning device. The methodcomprises sensing a displacement of the robotic cleaning device,determining a characteristic of the displacement of the robotic cleaningdevice, and setting the to robotic cleaning device in an operationalmode being associated with the determined characteristic of thedisplacement.

This object is attained in a second aspect of the invention by a roboticcleaning device comprising an inertia measurement unit and a controller.The inertia measurement unit is arranged to sense a displacement of therobotic cleaning device and the controller is arranged to determine acharacteristic of the displacement of the robotic cleaning device, andto set the robotic cleaning device in an operational mode beingassociated with the determined characteristic of the displacement.

Advantageously, by sensing at the robotic cleaning device a displacementof the device caused by a user, for instance by means of sensing thedisplacement with an inertial measurement unit (IMU), the robotic deviceis capable of determining a characteristic of the sensed displacement,such as a change in orientation or rotational velocity.

Based on the determined characteristic, the robotic cleaning device isset in a particular operational mode (possibly one out of a plurality ofoperational modes). For instance, if the user would lift the roboticdevice up from the floor and shake it back and forth, the robotic devicecould be configured to be set in an operational mode defined as “reset”in terms of setup preferences, or in case the robotic device is in theprocess of carrying through a cleaning program, the same operation oflifting the robotic device up from the floor and shake it back and forthcould be configured to imply “start over”. The act of lifting therobotic device from the floor up to a certain height above the floor mayin itself indicate that the displacement is caused by a user and not theresult of a normal displacement.

Thus, it is advantageously facilitated for a user to provide the roboticdevice with instructions without having to operate the UI of the roboticdevice. Further advantageous is that this may be provided with alreadyavailable hardware to means in the form of the IMU, as robotic cleaningdevices typically are arranged with one or more IMUs.

In an embodiment of the invention, the selected operational mode isfurther based on a current operational mode of the robotic cleaningdevice; if the current operational mode e.g. is “located in chargingstation”, the shaking could advantageously imply “reset”, while if thecurrent operational mode for instance is “running cleaning program A”,the same shaking motion of the user could advantageously imply “startover”.

In a further embodiment of the invention, the setting of the roboticcleaning device in an operational mode being associated with thedetermined characteristic of the displacement advantageously comprisesenabling wireless setup of the robotic cleaning device to a WirelessLocal Area Network (WLAN) when displaced to a predetermined orientation.In this particular exemplifying embodiment, the user may pick therobotic device up from the floor and for instance turn it upside downThe IMU of the robotic device will sense this displacement, and thecontroller registers the displacement caused by the user and sensed bythe IMU. The controller will in this embodiment determine thecharacteristic of displacement simply by concluding from IMU data thatthe robotic device is upside down and set the robot in a wireless setupmode.

In the wireless setup mode, the robotic device will advantageouslycommunicate wirelessly, for example via Bluetooth, with a mobileterminal of the user. The mobile terminal will then via a particular apptransfer the name of a WLAN of the user and the required password, suchthat the robotic device subsequently can connect to the WLAN provided byan Access Point (AP) such as e.g. a home router for wireless WiFicommunication.

In yet a further embodiment of the present invention, in order to avoida situation where the user would set the robotic cleaning device in anoperational mode with a displacement that could occur when the roboticdevice moves about to during normal operation, and thus accidentallyhave the robot itself enter the operational mode during performance of anormal cleaning program, the operational mode to be set is configured tobe associated with a characteristic of displacement which deviates froma characteristic corresponding to a displacement occurring during normaloperation of the robotic cleaning device.

Generally, all terms used in the claims are to be interpreted accordingto their ordinary meaning in the technical field, unless explicitlydefined otherwise herein. All references to “a/an/the element,apparatus, component, means, step, etc.” are to be interpreted openly asreferring to at least one instance of the element, apparatus, component,means, step, etc., unless explicitly stated otherwise. The steps of anymethod disclosed herein do not have to be performed in the exact orderdisclosed, unless explicitly stated.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now described, by way of example, with reference to theaccompanying drawings, in which:

FIG. 1 shows a bottom view of a robotic cleaning device according toembodiments of the present invention;

FIG. 2 shows a front view of a robotic cleaning device according toembodiments of the present invention;

FIG. 3a shows a top view of a robotic cleaning device being displacedaccording to an embodiment of the present invention;

FIG. 3b illustrates a flow chart of an embodiment of a method ofcontrolling a robotic cleaning device according to the presentinvention;

FIG. 4 shows a top view of a robotic cleaning device being displacedaccording to another embodiment of the present invention;

FIG. 5 illustrates a flow chart of another embodiment of a method ofcontrolling a robotic cleaning device according to the presentinvention; and

FIG. 6 illustrates a further operational mode being set according to anembodiment of the present invention.

DETAILED DESCRIPTION

The invention will now be described more fully hereinafter withreference to the accompanying drawings, in which certain embodiments ofthe invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided byway of example so that this disclosure will be thorough and complete,and will fully convey the scope of the invention to those skilled in theart. Like numbers refer to like elements throughout the description.

The invention relates to robotic cleaning devices, or in other words, toautomatic, self-propelled machines for cleaning a surface, e.g. arobotic vacuum cleaner, a robotic sweeper or a robotic floor washer. Therobotic cleaning device according to the invention can be mains-operatedand have a cord, be battery-operated or use any other kind of suitableenergy source, for example solar energy.

FIG. 1 shows a robotic cleaning device 10 according to embodiments ofthe present invention in a bottom view, i.e. the bottom side of therobotic cleaning device is shown. The arrow indicates the forwarddirection of the robotic cleaning device. The robotic cleaning device 10comprises a main body 11 housing components such as a propulsion systemcomprising driving means in the form of two electric wheel motors 15 a,15 b for enabling movement of the driving wheels 12, 13 such that thecleaning device can be moved over a surface to be cleaned. Each wheelmotor 15 a, 15 b is capable of controlling the respective driving wheel12, 13 to rotate independently of each other in order to move therobotic cleaning device 10 across the surface to be cleaned. A number ofdifferent driving wheel arrangements, as well as various wheel motorarrangements, can be envisaged. It should be noted that the roboticcleaning device may have any appropriate shape, such as a device havinga more traditional circular-shaped main body, or a triangular-shapedmain body. As an alternative, a track propulsion system may be used oreven a hovercraft propulsion system. The propulsion system may furtherbe arranged to cause the robotic cleaning device 10 to perform any oneor more of a yaw, pitch, translation or roll movement.

A controller 16 such as a microprocessor controls the wheel motors 15 a,15 b to rotate the driving wheels 12, 13 as required in view ofinformation received from an obstacle detecting device (not shown inFIG. 1) for detecting obstacles in the form of walls, floor lamps, tablelegs, around which the robotic cleaning device must navigate. Theobstacle detecting device may be embodied in the form of a 3D sensorsystem registering its surroundings, implemented by means of e.g. a 3Dcamera, a camera in combination with lasers, a laser scanner, etc. fordetecting obstacles and communicating information about any detectedobstacle to the microprocessor 16. The microprocessor 16 communicateswith the wheel motors 15 a, 15 b to control movement of the wheels 12,13 in accordance with information provided by the obstacle detectingdevice such that the robotic cleaning device 10 can move as desiredacross the surface to be cleaned. This will be described in more detailwith reference to subsequent drawings.

Further, the main body 11 may optionally be arranged with a cleaningmember 17 for removing debris and dust from the surface to be cleaned inthe form of a rotatable brush roll arranged in an opening 18 at thebottom of the robotic cleaner 10. Thus, the rotatable brush roll 17 isarranged along a horizontal axis in the opening 18 to enhance the dustand debris collecting properties of the cleaning device 10. In order torotate the brush roll 17, a brush roll motor 19 is to operativelycoupled to the brush roll to control its rotation in line withinstructions received from the controller 16.

Moreover, the main body 11 of the robotic cleaner 10 comprises a suctionfan 20 creating an air flow for transporting debris to a dust bag orcyclone arrangement (not shown) housed in the main body via the opening18 in the bottom side of the main body 11. The suction fan 20 is drivenby a fan motor 21 communicatively connected to the controller 16 fromwhich the fan motor 21 receives instructions for controlling the suctionfan 20. It should be noted that a robotic cleaning device having eitherone of the rotatable brush roll 17 and the suction fan 20 fortransporting debris to the dust bag can be envisaged. A combination ofthe two will however enhance the debris-removing capabilities of therobotic cleaning device 10.

The main body 11 or the robotic cleaning device 10 is further equippedwith an inertia measurement unit (IMU) 24, such as e.g. a gyroscopeand/or an accelerometer and/or a magnetometer or any other appropriatedevice for measuring displacement of the robotic cleaning device 10 withrespect to a reference position, in the form of e.g. orientation,rotational velocity, gravitational forces, etc. A three-axis gyroscopeis capable of measuring rotational velocity in a roll, pitch and yawmovement of the robotic cleaning device 10. A three-axis accelerometeris capable of measuring acceleration in all directions, which is mainlyused to determine whether the robotic cleaning device is bumped orlifted or if it is stuck (i.e. not moving even though the wheels areturning). The robotic cleaning device 10 further comprises encoders (notshown in FIG. 1) on each drive wheel 12, 13 which generate pulses whenthe wheels turn. The encoders may for instance be magnetic or optical.By counting the pulses at the controller 16, the speed of each wheel 12,13 can be determined. By combining wheel speed readings with gyroscopeinformation, the controller 16 can perform so called dead reckoning todetermine position and heading of the cleaning device 10.

The main body 11 may further be arranged with a rotating side brush 14adjacent to the opening 18, the rotation of which could be controlled bythe drive motors 15 a, 15 b, the brush roll motor 19, or alternatively aseparate side brush motor (not shown). Advantageously, the rotating sidebrush 14 sweeps debris and dust such from the surface to be cleaned suchthat the debris ends up under the main body 11 at the opening 18 andthus can be transported to a dust chamber of the robotic cleaningdevice. Further advantageous is that the reach of the robotic cleaningdevice 10 will be improved, and e.g. corners and areas where a floormeets a wall are much more effectively cleaned. As is illustrated inFIG. 1, the rotating side brush 14 rotates in a direction such that itsweeps debris towards the opening 18 such that the suction fan 20 cantransport the debris to a dust chamber. The robotic cleaning device 10may comprise two rotating side brushes arranged laterally on each sideof, and adjacent to, the opening 18.

With further reference to FIG. 1, the controller/processing unit 16embodied in the form of one or more microprocessors is arranged toexecute a computer program 25 downloaded to a suitable storage medium 26associated with the microprocessor, such as a Random Access Memory(RAM), a Flash memory or a hard disk drive. The controller 16 isarranged to carry out a method according to embodiments of the presentinvention when the appropriate computer program comprisingcomputer-executable instructions is downloaded to the storage medium 26and executed by the controller 16. The storage medium 26 may also be acomputer program product comprising the computer program 25.Alternatively, the computer program 25 may be transferred to the storagemedium 26 by means of a suitable computer program product, such as adigital versatile disc (DVD), compact disc (CD) or a memory stick. As afurther alternative, the computer program 25 may be downloaded to thestorage medium 26 over a wired or wireless network. The controller 16may alternatively be embodied in the form of a digital signal processor(DSP), an application specific integrated circuit (ASIC), afield-programmable gate array (FPGA), a complex programmable logicdevice (CPLD), etc.

FIG. 2 shows a front view of the robotic cleaning device 10 of FIG. 1 inan embodiment of the present invention illustrating the previouslymentioned obstacle detecting device in the form of a 3D sensor systemcomprising at least a camera 23 and a first and a second line laser 27,28, which may be horizontally or vertically oriented line lasers.Further shown is the controller 16, the main body 11, the driving wheels12, 13, and the rotatable brush roll 17 previously discussed withreference to FIG. 1a . The controller 16 is operatively coupled to thecamera 23 for recording images of a vicinity of the robotic cleaningdevice 10. The first and second line lasers 27, 28 may preferably bevertical line lasers and are arranged lateral of the camera 23 andconfigured to illuminate a height and a width that is greater than theheight and width of the robotic cleaning device 10. Further, the angleof the field of view of the camera 23 is preferably smaller than thespace illuminated by the first and second line lasers 27, 28. The camera23 is controlled by the controller 16 to capture and record a pluralityof images per second. Data from the images is extracted by thecontroller 16 and the data is typically saved in the memory 26 alongwith the computer program 25.

The first and second line lasers 27, 28 are typically arranged on arespective side of the camera 23 along an axis being perpendicular to anoptical axis of the camera. Further, the line lasers 27, 28 are directedsuch that their respective laser beams intersect within the field ofview of the camera 23. Typically, the intersection coincides with theoptical axis of the camera 23.

The first and second line laser 27, 28 are configured to scan,preferably in a vertical orientation, the vicinity of the roboticcleaning device 10, normally in the direction of movement of the roboticcleaning device 10. The first and second line lasers 27, 28 areconfigured to send out laser beams, which illuminate furniture, wallsand other objects of e.g. a room to be cleaned. The camera 23 iscontrolled by the controller 16 to capture and record images from whichthe controller 16 creates a representation or layout of the surroundingsthat the robotic cleaning device 10 is operating in, by extractingfeatures from the images and by measuring the distance covered by therobotic cleaning device 10, while the robotic cleaning device 10 ismoving across the surface to be cleaned. Thus, the controller 16 derivespositional data of the robotic cleaning device 10 with respect to thesurface to be cleaned from the recorded images, generates a 3Drepresentation of the surroundings from the derived positional data andcontrols the driving motors 15 a, 15 b to move the robotic cleaningdevice across the surface to be cleaned in accordance with the generated3D representation and navigation information supplied to the roboticcleaning device 10 such that the surface to be cleaned can be navigatedby taking into account the generated 3D representation. Since thederived positional data will serve as a foundation for the navigation ofthe robotic cleaning device, it is important that the positioning iscorrect; the robotic device will otherwise navigate according to a “map”of its surroundings that is misleading.

The 3D representation generated from the images recorded by the 3Dsensor system thus facilitates detection of obstacles in the form ofwalls, floor lamps, table legs, around which the robotic cleaning devicemust navigate as well as rugs, carpets, doorsteps, etc., that therobotic cleaning device 10 must traverse. The robotic cleaning device 10is hence configured to learn about its environment or surroundings byoperating/cleaning.

Hence, the 3D sensor system comprising the camera 23 and the first andsecond vertical line lasers 27, 28 is arranged to record images of avicinity of the robotic cleaning from which objects/obstacles may bedetected. The controller 16 is capable of positioning the roboticcleaning device 10 with respect to the detected obstacles and hence asurface to be cleaned by deriving positional data from the recordedimages. From the positioning, the controller 16 controls movement of therobotic cleaning device 10 by means of controlling the wheels 12, 13 viathe to wheel drive motors 15 a, 15 b, across the surface to be cleaned.

The derived positional data facilitates control of the movement of therobotic cleaning device 10 such that cleaning device can be navigated tomove very close to an object, and to move closely around the object toremove debris from the surface on which the object is located. Hence,the derived positional data is utilized to move flush against theobject, being e.g. a thick rug or a wall. Typically, the controller 16continuously generates and transfers control signals to the drive wheels12, 13 via the drive motors 15 a, 15 b such that the robotic cleaningdevice 10 is navigated close to the object.

With reference to FIG. 3a , where the robotic device 10 is illustratedin a top view, assuming that a user would want to provide the roboticvacuum cleaner 10 with a particular type of instruction withoutoperating a user interface 29, in this particular exemplifyingembodiment an instruction specifying that the robotic cleaning device 10is to be “reset” or “start over” as will be discussed in more detail inthe following. This instruction is communicated to the robotic device 10by having the user picking the robot 10 up from the floor and shaking itback and forth as illustrated in FIG. 3 a.

The UI 29 may be of touch-screen type or mechanically configuredcomprising physical buttons to be operated. Further, the user interface29 may comprise display means for visually indicating a user selection.It should be noted that the user not necessarily need to provide inputto the UI 29 by physically touching the UI, but may alternativelycommunicate with the UI 29 via a remote control.

The user behaviour described with reference to FIG. 3a causes therobotic device to perform a method according to an embodiment of theinvention for controlling the robotic cleaning device 10, FIG. 3billustrates a flowchart of this embodiment of the method. Reference isfurther made to FIG. 1 for structural elements.

Thus, the user picks the robot 10 up from the floor and shakes it backand forth. The IMU 24 of the robotic device 10 will sense thisdisplacement in step S101, and the controller 16 will accordinglyregister the sensed displacement brought about by the user. Now, uponregistering the displacement sensed by the IMU 24, the controller 16will determine a characteristic of the displacement in step S102, inthis particular example being that the robotic device is shaken back andforth, i.e. brought from a first position in a particular direction to asecond position and subsequently being brought back to the firstposition from the second position in a substantially reverse direction.This characteristic may be determined by the controller 16 for instanceby having the IMU 24 measure a change in orientation and possiblyvelocity of the robotic device 10 as it is shaken by the user.

Thereafter, in step S103, the controller 16 sets the robotic cleaningdevice in an operational mode associated with the determinedcharacteristic.

Now, in this particular example, if the robotic device 10 is temporarilyinactive, for instance being charged in its charging station, thisparticular instruction provided by the user may imply that the roboticcleaning device 10 is reset in terms of registered upcoming cleaningprograms. These are generally stored in the memory 25, and thecontroller 16 may thus erase such registered upcoming cleaning programsin favour of a “reset” default setup.

However, in case the robotic device 10 is in the process of performing acleaning program, the operation of picking the robotic device up fromthe floor and shake it back and forth could be configured to imply thatthe current cleaning program should start over.

Hence, in an embodiment of the invention, the selected operational modeis further based on a current operational mode of the robotic cleaningdevice 10; if the current operational mode e.g. is “located in chargingstation”, the shaking could imply “reset”, while if the currentoperational mode for instance is “running cleaning program A”, the sameshaking motion of the user could imply “start over”.

With reference to FIG. 4, in another exemplifying embodiment, the usercauses displacement of the robotic cleaning device by rotating it from a“12 o'clock” orientation to a “2 o'clock” orientation in order toprovide the robot 10 with a particular instruction. The IMU 24 may thussense a change in the orientation, and the controller 16 determines thatthis particular characteristic of the displacement, i.e. a change inorientation from “12 o'clock” to “2 o'clock”, is associated with a givenoperational mode, such as a change from a normal-energy mode to a a-lowenergy “eco” mode.

It can further be envisaged that a particular sequence of displacementsindicates a particular operational mode to be set. For instance,assuming that the user would want a current cleaning program to finishat an earlier stage than expected, and have the robotic cleaning device10 return to the charging station, the user may lightly kick the roboticdevice three times in a sequence to cause three sequential slightdisplacements, to have the controller 16 finish the program and returnto the charging station. Any operational mode could practically be setgiven that it is predefined in the robotic device 10 and associated witha particular characteristic of the displacement caused by the user.

It should further be noted that the characteristic of the displacementof the robotic cleaning device 10 not necessarily must be determinedbased on a reference position, but could alternatively be a relativecharacteristic. For instance, with reference to the previousexemplifying embodiment where the robotic cleaning device is displacedby rotating it from a “12 o'clock” orientation to a “2 o'clock”orientation; the same instruction could be provided to the robot byperforming the same relative rotation, such as for instance from a “4o'clock” orientation to a “6 o'clock” orientation, as the controllerwill determine the same characteristic of displacement. Further,depending on a rotational velocity to sensed by the IMU 24, the speedwith which the robot is rotated could itself imply a particular cleaningprogram, where for instance a rotation of the robot at a first velocitywould imply a first operational mode, while the same rotation of therobot 10 at a second velocity would imply a second operational mode.

FIG. 5 shows a flowchart illustrating a further embodiment of the methodof the invention of controlling the operation of the robotic cleaningdevice 10. In this particular exemplifying embodiment, the user picksthe robotic device 10 up from the floor and turns it upside down, withits UI 29 facing the floor. As can be seen in the look-up table(typically stored in the memory 25 of the robotic cleaning device 10) ofFIG. 5, a displacement caused by flipping the robot upside down wouldimply that the user wants to set the robot 10 in a wireless setup mode,for instance for having the robot 10 connecting via an air interface toa smart phone of the user, the phone running an appropriate app forcommunicating with the robot 10.

The IMU 24 of the robotic device 10 will sense this displacement in stepS101, and the controller 16 registers the displacement caused by theuser and sensed by the IMU 24. The controller 16 will in this embodimentdetermine the characteristic of displacement in step S102 simply byconcluding from IMU data that the robotic device 10 is upside down. Thisdetermined characteristic, i.e. in practice a value of a IMU reading, iscompared by the controller 16 to entries A, B and C in the look-up tablein step S103 a, wherein it is determined that there is a match withpre-stored characteristic C. Each pre-stored characteristic isassociated with a corresponding operational mode and as can be deducted,a displacement by the user causing the robot 10 to be orientated upsidedown will have the controller 16 set the robot in “wireless setup” modein step S103.

With reference to FIG. 6, in the wireless setup mode, the robot 10 willcommunicate wirelessly, for example via Bluetooth, with a mobileterminal 30 (such as a smart phone) of the user. The smart phone 30 willthen via a to particular app transfer the name of a Wireless Local AreaNetwork (WLAN) of the user and the required password (if any), such thatthe robot 10 subsequently can connect to the WLAN provided by an AccessPoint (AP) 31 such as e.g. a home router for wireless WiFicommunication. It can be envisaged that the robot 10 should be turnedback into its normal position in order to exit the wireless setup modeand enter WiFi mode. In this particular embodiment, the controller 16 iseither arranged with transceiver functionality or controls a separatetransceiver device (not shown) for performing wireless communication.

Thus, the displacement sensed by the IMU 24 may include both a staticchange in orientation (such as the robot 10 being upside down) anddynamic changes in orientation (i.e. the user quickly turns the robot 10in a particular direction and returns it to its original position).

In an embodiment of the present invention, in order to avoid a situationwhere the user would set the robotic cleaning device in an operationalmode with a displacement that very well could occur when the roboticdevice moves about during normal operation, and thus accidentally havethe robot itself enter the operational mode during performance of anormal cleaning program, the operational mode to be set is configured tobe associated with a characteristic of displacement which deviates froma characteristic corresponding to a displacement occurring during normaloperation of the robotic cleaning device.

Thus, with reference to the properties of displacement illustrated inthe look-up table of FIG. 5, it can be concluded that possible theactions to be taken by the user to set the robotic cleaning device in adesired operational mode should be selected such that they do notcoincide with “normal” behaviour of the robotic device. With referenceto the look-up table, during normal operation the robotic device couldnot be operated such that it mimics any one of the properties A, B andC.

The invention has mainly been described above with reference to a fewembodiments. However, as is readily appreciated by a person skilled inthe art, other embodiments than the ones disclosed above are equallypossible within the scope of the invention, as defined by the appendedpatent claims.

The invention claimed is:
 1. A method of controlling operation of arobotic cleaning device, the method comprising: sensing a displacementof the robotic cleaning device; determining a characteristic of thedisplacement of the robotic cleaning device; compare the determinedcharacteristic of the displacement with a plurality of differentpredetermined characteristics of the displacement, and based on thecomparison, determining a match between the determined characteristic ofthe displacement and a matching one of the plurality of differentpredetermined characteristics of the displacement, wherein each of theplurality of different predetermined characteristics of the displacementare associated with a different one of a plurality of predeterminedoperational modes of the robotic cleaning device; and setting therobotic cleaning device in an associated one of the plurality ofpredetermined operational modes that is associated with the matching oneof the plurality of different predetermined characteristics ofdisplacement, wherein the characteristic of the displacement is amovement pattern where the robotic cleaning device is maneuvered by auser.
 2. The method according to claim 1, wherein the operational modeto be set is configured to be associated with a characteristic ofdisplacement which deviates from a characteristic corresponding to adisplacement occurring during normal operation of the robotic cleaningdevice.
 3. The method according to any one of claim 1, wherein thedetermined characteristic of the displacement corresponds to a patternof movement of the robotic cleaning device caused by a user displacingthe robotic cleaning device.
 4. The method according to claim 3, whereinthe determined characteristic of the displacement comprises a change inorientation of the robotic cleaning device.
 5. The method according toclaim 3, wherein the determined characteristic of the displacementcomprises a change in velocity of the robotic cleaning device.
 6. Themethod according to claim 1, wherein the setting of the robotic cleaningdevice in the operational mode comprises: comparing the determinedcharacteristic of the displacement to a pre-stored characteristic ofdisplacement, the pre-stored characteristic of displacement beingassociated with a particular operational mode; identifying acorrespondence between the determined characteristic of the displacementand the pre-stored characteristic of displacement; and setting therobotic cleaning device in the particular operational mode associatedwith the pre-stored characteristic of displacement.
 7. The methodaccording to claim 1, wherein the setting of the robotic cleaning devicein the operational mode associated with the determined characteristic ofthe displacement further is based upon a current operational mode of therobotic cleaning device.
 8. The method according to claim 1, wherein thesetting of the robotic cleaning device in the operational modeassociated with the determined characteristic of the displacementcomprises: enabling wireless setup of the robotic cleaning device to aWireless Local Area Network, when the robotic cleaning device isdisplaced to a predetermined orientation.
 9. The method of claim 1,wherein the plurality of different predetermined characteristics of thedisplacement includes at least two of the robot being turned upside downby the user, the robot being shaken by the user, and the robot beingrotated by the user.
 10. The method of claim 9, wherein the plurality ofpredetermined operational modes of the robotic cleaning device includesat least two of the robot enabling a wireless setup, the robot beingreset, and the robot entering an economical mode.
 11. A robotic cleaningdevice comprising: an inertia measurement unit configured to sense adisplacement of the robotic cleaning device; and a controller configuredto: determine a characteristic of the displacement of the roboticcleaning device, compare the determined characteristic of thedisplacement with a plurality of different predetermined characteristicsof the displacement, and based on the comparison, determining a matchbetween the determined characteristic of the displacement and a matchingone of the plurality of different predetermined characteristics of thedisplacement, wherein each of the plurality of different predeterminedcharacteristics of the displacement are associated with a different oneof a plurality of predetermined operational modes of the roboticcleaning device, and set the robotic cleaning device in an associatedone of the plurality of predetermined operational modes that isassociated with the matching one of the plurality of differentpredetermined characteristics of displacement, wherein thecharacteristic of the displacement is a movement pattern where therobotic cleaning device is maneuvered by a user.
 12. The roboticcleaning device according to claim 11, wherein the operational mode tobe set is configured to be associated with a characteristic ofdisplacement which deviates from a characteristic corresponding to adisplacement occurring during normal operation of the robotic cleaningdevice.
 13. The robotic cleaning device according to claim 11, whereinthe determined characteristic of the displacement corresponds to apattern of movement of the robotic cleaning device caused by a userdisplacing the robotic cleaning device.
 14. The robotic cleaning deviceaccording to claim 11, wherein the determined characteristic of thedisplacement comprises a change in orientation of the robotic cleaningdevice.
 15. The robotic cleaning device according to claim 11, whereinthe determined characteristic of the displacement comprises a change invelocity of the robotic cleaning device.
 16. The robotic cleaning deviceaccording to claim 11, wherein the controller further is arranged, whensetting the robotic cleaning device in the operational mode, to: comparethe determined characteristic of the displacement to a pre-storedcharacteristic of displacement, the pre-stored characteristic ofdisplacement being associated with a particular operational mode; andidentify a correspondence between the determined characteristic of thedisplacement and the pre-stored characteristic of displacement; and setthe robotic cleaning device in the particular operational modeassociated with the pre-stored characteristic of displacement.
 17. Therobotic cleaning device according to claim 11, wherein the controller isarranged to set the robotic cleaning device in the operational modeassociated with the determined characteristic of the displacement bytaking into account a current operational mode of the robotic cleaningdevice.
 18. The robotic cleaning device according to claim 11, whereinthe controller is arranged, when setting the robotic cleaning device inthe operational mode associated with the determined characteristic ofthe displacement, to: enable wireless setup of the robotic cleaningdevice to a Wireless Local Area Network when the robotic cleaning deviceis displaced to a predetermined orientation.
 19. The robotic cleaningdevice according to claim 11, wherein the plurality of differentpredetermined characteristics of the displacement includes at least twoof the robot being turned upside down by the user, the robot beingshaken by the user, and the robot being rotated by the user.
 20. Therobotic cleaning device according to claim 11, wherein the plurality ofpredetermined operational modes of the robotic cleaning device includesat least two of the robot enabling a wireless setup, the robot beingreset, and the robot entering an economical mode.